It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Alpha/AlphaISelLowering.cpp b/lib/Target/Alpha/AlphaISelLowering.cpp
new file mode 100644
index 0000000..d4777b2
--- /dev/null
+++ b/lib/Target/Alpha/AlphaISelLowering.cpp
@@ -0,0 +1,623 @@
+//===-- AlphaISelLowering.cpp - Alpha DAG Lowering Implementation ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Andrew Lenharth and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the AlphaISelLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AlphaISelLowering.h"
+#include "AlphaTargetMachine.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/SSARegMap.h"
+#include "llvm/Constants.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+/// AddLiveIn - This helper function adds the specified physical register to the
+/// MachineFunction as a live in value.  It also creates a corresponding virtual
+/// register for it.
+static unsigned AddLiveIn(MachineFunction &MF, unsigned PReg,
+                          TargetRegisterClass *RC) {
+  assert(RC->contains(PReg) && "Not the correct regclass!");
+  unsigned VReg = MF.getSSARegMap()->createVirtualRegister(RC);
+  MF.addLiveIn(PReg, VReg);
+  return VReg;
+}
+
+AlphaTargetLowering::AlphaTargetLowering(TargetMachine &TM) : TargetLowering(TM) {
+  // Set up the TargetLowering object.
+  //I am having problems with shr n ubyte 1
+  setShiftAmountType(MVT::i64);
+  setSetCCResultType(MVT::i64);
+  setSetCCResultContents(ZeroOrOneSetCCResult);
+  
+  setUsesGlobalOffsetTable(true);
+  
+  addRegisterClass(MVT::i64, Alpha::GPRCRegisterClass);
+  addRegisterClass(MVT::f64, Alpha::F8RCRegisterClass);
+  addRegisterClass(MVT::f32, Alpha::F4RCRegisterClass);
+  
+  setLoadXAction(ISD::EXTLOAD, MVT::i1,  Promote);
+  setLoadXAction(ISD::EXTLOAD, MVT::f32, Expand);
+  
+  setLoadXAction(ISD::ZEXTLOAD, MVT::i1,  Promote);
+  setLoadXAction(ISD::ZEXTLOAD, MVT::i32, Expand);
+  
+  setLoadXAction(ISD::SEXTLOAD, MVT::i1,  Promote);
+  setLoadXAction(ISD::SEXTLOAD, MVT::i8,  Expand);
+  setLoadXAction(ISD::SEXTLOAD, MVT::i16, Expand);
+
+  setStoreXAction(MVT::i1, Promote);
+  
+  //  setOperationAction(ISD::BRIND,        MVT::Other,   Expand);
+  setOperationAction(ISD::BR_JT,        MVT::Other, Expand);
+  setOperationAction(ISD::BR_CC,        MVT::Other, Expand);
+  setOperationAction(ISD::SELECT_CC,    MVT::Other, Expand);  
+
+  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
+
+  setOperationAction(ISD::FREM, MVT::f32, Expand);
+  setOperationAction(ISD::FREM, MVT::f64, Expand);
+  
+  setOperationAction(ISD::UINT_TO_FP, MVT::i64, Expand);
+  setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
+  setOperationAction(ISD::FP_TO_UINT, MVT::i64, Expand);
+  setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
+
+  if (!TM.getSubtarget<AlphaSubtarget>().hasCT()) {
+    setOperationAction(ISD::CTPOP    , MVT::i64  , Expand);
+    setOperationAction(ISD::CTTZ     , MVT::i64  , Expand);
+    setOperationAction(ISD::CTLZ     , MVT::i64  , Expand);
+  }
+  setOperationAction(ISD::BSWAP    , MVT::i64, Expand);
+  setOperationAction(ISD::ROTL     , MVT::i64, Expand);
+  setOperationAction(ISD::ROTR     , MVT::i64, Expand);
+  
+  setOperationAction(ISD::SREM     , MVT::i64, Custom);
+  setOperationAction(ISD::UREM     , MVT::i64, Custom);
+  setOperationAction(ISD::SDIV     , MVT::i64, Custom);
+  setOperationAction(ISD::UDIV     , MVT::i64, Custom);
+
+  setOperationAction(ISD::MEMMOVE  , MVT::Other, Expand);
+  setOperationAction(ISD::MEMSET   , MVT::Other, Expand);
+  setOperationAction(ISD::MEMCPY   , MVT::Other, Expand);
+  
+  // We don't support sin/cos/sqrt
+  setOperationAction(ISD::FSIN , MVT::f64, Expand);
+  setOperationAction(ISD::FCOS , MVT::f64, Expand);
+  setOperationAction(ISD::FSIN , MVT::f32, Expand);
+  setOperationAction(ISD::FCOS , MVT::f32, Expand);
+
+  setOperationAction(ISD::FSQRT, MVT::f64, Expand);
+  setOperationAction(ISD::FSQRT, MVT::f32, Expand);
+  
+  setOperationAction(ISD::SETCC, MVT::f32, Promote);
+
+  setOperationAction(ISD::BIT_CONVERT, MVT::f32, Promote);
+
+  // We don't have line number support yet.
+  setOperationAction(ISD::LOCATION, MVT::Other, Expand);
+  setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
+  setOperationAction(ISD::LABEL, MVT::Other, Expand);
+
+  // Not implemented yet.
+  setOperationAction(ISD::STACKSAVE, MVT::Other, Expand); 
+  setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
+  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Expand);
+
+  // We want to legalize GlobalAddress and ConstantPool and
+  // ExternalSymbols nodes into the appropriate instructions to
+  // materialize the address.
+  setOperationAction(ISD::GlobalAddress,  MVT::i64, Custom);
+  setOperationAction(ISD::ConstantPool,   MVT::i64, Custom);
+  setOperationAction(ISD::ExternalSymbol, MVT::i64, Custom);
+  setOperationAction(ISD::GlobalTLSAddress, MVT::i64, Custom);
+
+  setOperationAction(ISD::VASTART, MVT::Other, Custom);
+  setOperationAction(ISD::VAEND,   MVT::Other, Expand);
+  setOperationAction(ISD::VACOPY,  MVT::Other, Custom);
+  setOperationAction(ISD::VAARG,   MVT::Other, Custom);
+  setOperationAction(ISD::VAARG,   MVT::i32,   Custom);
+
+  setOperationAction(ISD::RET,     MVT::Other, Custom);
+
+  setOperationAction(ISD::JumpTable, MVT::i64, Custom);
+  setOperationAction(ISD::JumpTable, MVT::i32, Custom);
+
+  setStackPointerRegisterToSaveRestore(Alpha::R30);
+
+  setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
+  setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
+  addLegalFPImmediate(+0.0); //F31
+  addLegalFPImmediate(-0.0); //-F31
+
+  setJumpBufSize(272);
+  setJumpBufAlignment(16);
+
+  computeRegisterProperties();
+}
+
+const char *AlphaTargetLowering::getTargetNodeName(unsigned Opcode) const {
+  switch (Opcode) {
+  default: return 0;
+  case AlphaISD::CVTQT_: return "Alpha::CVTQT_";
+  case AlphaISD::CVTQS_: return "Alpha::CVTQS_";
+  case AlphaISD::CVTTQ_: return "Alpha::CVTTQ_";
+  case AlphaISD::GPRelHi: return "Alpha::GPRelHi";
+  case AlphaISD::GPRelLo: return "Alpha::GPRelLo";
+  case AlphaISD::RelLit: return "Alpha::RelLit";
+  case AlphaISD::GlobalRetAddr: return "Alpha::GlobalRetAddr";
+  case AlphaISD::CALL:   return "Alpha::CALL";
+  case AlphaISD::DivCall: return "Alpha::DivCall";
+  case AlphaISD::RET_FLAG: return "Alpha::RET_FLAG";
+  case AlphaISD::COND_BRANCH_I: return "Alpha::COND_BRANCH_I";
+  case AlphaISD::COND_BRANCH_F: return "Alpha::COND_BRANCH_F";
+  }
+}
+
+static SDOperand LowerJumpTable(SDOperand Op, SelectionDAG &DAG) {
+  MVT::ValueType PtrVT = Op.getValueType();
+  JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
+  SDOperand JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT);
+  SDOperand Zero = DAG.getConstant(0, PtrVT);
+  
+  SDOperand Hi = DAG.getNode(AlphaISD::GPRelHi,  MVT::i64, JTI,
+                             DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, MVT::i64));
+  SDOperand Lo = DAG.getNode(AlphaISD::GPRelLo, MVT::i64, JTI, Hi);
+  return Lo;
+}
+
+//http://www.cs.arizona.edu/computer.help/policy/DIGITAL_unix/
+//AA-PY8AC-TET1_html/callCH3.html#BLOCK21
+
+//For now, just use variable size stack frame format
+
+//In a standard call, the first six items are passed in registers $16
+//- $21 and/or registers $f16 - $f21. (See Section 4.1.2 for details
+//of argument-to-register correspondence.) The remaining items are
+//collected in a memory argument list that is a naturally aligned
+//array of quadwords. In a standard call, this list, if present, must
+//be passed at 0(SP).
+//7 ... n         0(SP) ... (n-7)*8(SP)
+
+// //#define FP    $15
+// //#define RA    $26
+// //#define PV    $27
+// //#define GP    $29
+// //#define SP    $30
+
+static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
+                                       int &VarArgsBase,
+                                       int &VarArgsOffset) {
+  MachineFunction &MF = DAG.getMachineFunction();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  std::vector<SDOperand> ArgValues;
+  SDOperand Root = Op.getOperand(0);
+
+  AddLiveIn(MF, Alpha::R29, &Alpha::GPRCRegClass); //GP
+  AddLiveIn(MF, Alpha::R26, &Alpha::GPRCRegClass); //RA
+
+  unsigned args_int[] = {
+    Alpha::R16, Alpha::R17, Alpha::R18, Alpha::R19, Alpha::R20, Alpha::R21};
+  unsigned args_float[] = {
+    Alpha::F16, Alpha::F17, Alpha::F18, Alpha::F19, Alpha::F20, Alpha::F21};
+  
+  for (unsigned ArgNo = 0, e = Op.Val->getNumValues()-1; ArgNo != e; ++ArgNo) {
+    SDOperand argt;
+    MVT::ValueType ObjectVT = Op.getValue(ArgNo).getValueType();
+    SDOperand ArgVal;
+
+    if (ArgNo  < 6) {
+      switch (ObjectVT) {
+      default:
+        cerr << "Unknown Type " << ObjectVT << "\n";
+        abort();
+      case MVT::f64:
+        args_float[ArgNo] = AddLiveIn(MF, args_float[ArgNo], 
+                                      &Alpha::F8RCRegClass);
+        ArgVal = DAG.getCopyFromReg(Root, args_float[ArgNo], ObjectVT);
+        break;
+      case MVT::f32:
+        args_float[ArgNo] = AddLiveIn(MF, args_float[ArgNo], 
+                                      &Alpha::F4RCRegClass);
+        ArgVal = DAG.getCopyFromReg(Root, args_float[ArgNo], ObjectVT);
+        break;
+      case MVT::i64:
+        args_int[ArgNo] = AddLiveIn(MF, args_int[ArgNo], 
+                                    &Alpha::GPRCRegClass);
+        ArgVal = DAG.getCopyFromReg(Root, args_int[ArgNo], MVT::i64);
+        break;
+      }
+    } else { //more args
+      // Create the frame index object for this incoming parameter...
+      int FI = MFI->CreateFixedObject(8, 8 * (ArgNo - 6));
+
+      // Create the SelectionDAG nodes corresponding to a load
+      //from this parameter
+      SDOperand FIN = DAG.getFrameIndex(FI, MVT::i64);
+      ArgVal = DAG.getLoad(ObjectVT, Root, FIN, NULL, 0);
+    }
+    ArgValues.push_back(ArgVal);
+  }
+
+  // If the functions takes variable number of arguments, copy all regs to stack
+  bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getValue() != 0;
+  if (isVarArg) {
+    VarArgsOffset = (Op.Val->getNumValues()-1) * 8;
+    std::vector<SDOperand> LS;
+    for (int i = 0; i < 6; ++i) {
+      if (MRegisterInfo::isPhysicalRegister(args_int[i]))
+        args_int[i] = AddLiveIn(MF, args_int[i], &Alpha::GPRCRegClass);
+      SDOperand argt = DAG.getCopyFromReg(Root, args_int[i], MVT::i64);
+      int FI = MFI->CreateFixedObject(8, -8 * (6 - i));
+      if (i == 0) VarArgsBase = FI;
+      SDOperand SDFI = DAG.getFrameIndex(FI, MVT::i64);
+      LS.push_back(DAG.getStore(Root, argt, SDFI, NULL, 0));
+
+      if (MRegisterInfo::isPhysicalRegister(args_float[i]))
+        args_float[i] = AddLiveIn(MF, args_float[i], &Alpha::F8RCRegClass);
+      argt = DAG.getCopyFromReg(Root, args_float[i], MVT::f64);
+      FI = MFI->CreateFixedObject(8, - 8 * (12 - i));
+      SDFI = DAG.getFrameIndex(FI, MVT::i64);
+      LS.push_back(DAG.getStore(Root, argt, SDFI, NULL, 0));
+    }
+
+    //Set up a token factor with all the stack traffic
+    Root = DAG.getNode(ISD::TokenFactor, MVT::Other, &LS[0], LS.size());
+  }
+
+  ArgValues.push_back(Root);
+
+  // Return the new list of results.
+  std::vector<MVT::ValueType> RetVT(Op.Val->value_begin(),
+                                    Op.Val->value_end());
+  return DAG.getNode(ISD::MERGE_VALUES, RetVT, &ArgValues[0], ArgValues.size());
+}
+
+static SDOperand LowerRET(SDOperand Op, SelectionDAG &DAG) {
+  SDOperand Copy = DAG.getCopyToReg(Op.getOperand(0), Alpha::R26, 
+                                    DAG.getNode(AlphaISD::GlobalRetAddr, 
+                                                MVT::i64),
+                                    SDOperand());
+  switch (Op.getNumOperands()) {
+  default:
+    assert(0 && "Do not know how to return this many arguments!");
+    abort();
+  case 1: 
+    break;
+    //return SDOperand(); // ret void is legal
+  case 3: {
+    MVT::ValueType ArgVT = Op.getOperand(1).getValueType();
+    unsigned ArgReg;
+    if (MVT::isInteger(ArgVT))
+      ArgReg = Alpha::R0;
+    else {
+      assert(MVT::isFloatingPoint(ArgVT));
+      ArgReg = Alpha::F0;
+    }
+    Copy = DAG.getCopyToReg(Copy, ArgReg, Op.getOperand(1), Copy.getValue(1));
+    if (DAG.getMachineFunction().liveout_empty())
+      DAG.getMachineFunction().addLiveOut(ArgReg);
+    break;
+  }
+  }
+  return DAG.getNode(AlphaISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
+}
+
+std::pair<SDOperand, SDOperand>
+AlphaTargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy, 
+                                 bool RetTyIsSigned, bool isVarArg,
+                                 unsigned CallingConv, bool isTailCall,
+                                 SDOperand Callee, ArgListTy &Args,
+                                 SelectionDAG &DAG) {
+  int NumBytes = 0;
+  if (Args.size() > 6)
+    NumBytes = (Args.size() - 6) * 8;
+
+  Chain = DAG.getCALLSEQ_START(Chain,
+                               DAG.getConstant(NumBytes, getPointerTy()));
+  std::vector<SDOperand> args_to_use;
+  for (unsigned i = 0, e = Args.size(); i != e; ++i)
+  {
+    switch (getValueType(Args[i].Ty)) {
+    default: assert(0 && "Unexpected ValueType for argument!");
+    case MVT::i1:
+    case MVT::i8:
+    case MVT::i16:
+    case MVT::i32:
+      // Promote the integer to 64 bits.  If the input type is signed use a
+      // sign extend, otherwise use a zero extend.
+      if (Args[i].isSExt)
+        Args[i].Node = DAG.getNode(ISD::SIGN_EXTEND, MVT::i64, Args[i].Node);
+      else if (Args[i].isZExt)
+        Args[i].Node = DAG.getNode(ISD::ZERO_EXTEND, MVT::i64, Args[i].Node);
+      else
+        Args[i].Node = DAG.getNode(ISD::ANY_EXTEND, MVT::i64, Args[i].Node);
+      break;
+    case MVT::i64:
+    case MVT::f64:
+    case MVT::f32:
+      break;
+    }
+    args_to_use.push_back(Args[i].Node);
+  }
+
+  std::vector<MVT::ValueType> RetVals;
+  MVT::ValueType RetTyVT = getValueType(RetTy);
+  MVT::ValueType ActualRetTyVT = RetTyVT;
+  if (RetTyVT >= MVT::i1 && RetTyVT <= MVT::i32)
+    ActualRetTyVT = MVT::i64;
+
+  if (RetTyVT != MVT::isVoid)
+    RetVals.push_back(ActualRetTyVT);
+  RetVals.push_back(MVT::Other);
+
+  std::vector<SDOperand> Ops;
+  Ops.push_back(Chain);
+  Ops.push_back(Callee);
+  Ops.insert(Ops.end(), args_to_use.begin(), args_to_use.end());
+  SDOperand TheCall = DAG.getNode(AlphaISD::CALL, RetVals, &Ops[0], Ops.size());
+  Chain = TheCall.getValue(RetTyVT != MVT::isVoid);
+  Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
+                      DAG.getConstant(NumBytes, getPointerTy()));
+  SDOperand RetVal = TheCall;
+
+  if (RetTyVT != ActualRetTyVT) {
+    RetVal = DAG.getNode(RetTyIsSigned ? ISD::AssertSext : ISD::AssertZext,
+                         MVT::i64, RetVal, DAG.getValueType(RetTyVT));
+    RetVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, RetVal);
+  }
+
+  return std::make_pair(RetVal, Chain);
+}
+
+/// LowerOperation - Provide custom lowering hooks for some operations.
+///
+SDOperand AlphaTargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
+  switch (Op.getOpcode()) {
+  default: assert(0 && "Wasn't expecting to be able to lower this!");
+  case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG, 
+                                                           VarArgsBase,
+                                                           VarArgsOffset);
+
+  case ISD::RET: return LowerRET(Op,DAG);
+  case ISD::JumpTable: return LowerJumpTable(Op, DAG);
+
+  case ISD::SINT_TO_FP: {
+    assert(MVT::i64 == Op.getOperand(0).getValueType() && 
+           "Unhandled SINT_TO_FP type in custom expander!");
+    SDOperand LD;
+    bool isDouble = MVT::f64 == Op.getValueType();
+    LD = DAG.getNode(ISD::BIT_CONVERT, MVT::f64, Op.getOperand(0));
+    SDOperand FP = DAG.getNode(isDouble?AlphaISD::CVTQT_:AlphaISD::CVTQS_,
+                               isDouble?MVT::f64:MVT::f32, LD);
+    return FP;
+  }
+  case ISD::FP_TO_SINT: {
+    bool isDouble = MVT::f64 == Op.getOperand(0).getValueType();
+    SDOperand src = Op.getOperand(0);
+
+    if (!isDouble) //Promote
+      src = DAG.getNode(ISD::FP_EXTEND, MVT::f64, src);
+    
+    src = DAG.getNode(AlphaISD::CVTTQ_, MVT::f64, src);
+
+    return DAG.getNode(ISD::BIT_CONVERT, MVT::i64, src);
+  }
+  case ISD::ConstantPool: {
+    ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
+    Constant *C = CP->getConstVal();
+    SDOperand CPI = DAG.getTargetConstantPool(C, MVT::i64, CP->getAlignment());
+    
+    SDOperand Hi = DAG.getNode(AlphaISD::GPRelHi,  MVT::i64, CPI,
+                               DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, MVT::i64));
+    SDOperand Lo = DAG.getNode(AlphaISD::GPRelLo, MVT::i64, CPI, Hi);
+    return Lo;
+  }
+  case ISD::GlobalTLSAddress:
+    assert(0 && "TLS not implemented for Alpha.");
+  case ISD::GlobalAddress: {
+    GlobalAddressSDNode *GSDN = cast<GlobalAddressSDNode>(Op);
+    GlobalValue *GV = GSDN->getGlobal();
+    SDOperand GA = DAG.getTargetGlobalAddress(GV, MVT::i64, GSDN->getOffset());
+
+    //    if (!GV->hasWeakLinkage() && !GV->isDeclaration() && !GV->hasLinkOnceLinkage()) {
+    if (GV->hasInternalLinkage()) {
+      SDOperand Hi = DAG.getNode(AlphaISD::GPRelHi,  MVT::i64, GA,
+                                DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, MVT::i64));
+      SDOperand Lo = DAG.getNode(AlphaISD::GPRelLo, MVT::i64, GA, Hi);
+      return Lo;
+    } else
+      return DAG.getNode(AlphaISD::RelLit, MVT::i64, GA, 
+                         DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, MVT::i64));
+  }
+  case ISD::ExternalSymbol: {
+    return DAG.getNode(AlphaISD::RelLit, MVT::i64, 
+                       DAG.getTargetExternalSymbol(cast<ExternalSymbolSDNode>(Op)
+                                                   ->getSymbol(), MVT::i64),
+                       DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, MVT::i64));
+  }
+
+  case ISD::UREM:
+  case ISD::SREM:
+    //Expand only on constant case
+    if (Op.getOperand(1).getOpcode() == ISD::Constant) {
+      MVT::ValueType VT = Op.Val->getValueType(0);
+      SDOperand Tmp1 = Op.Val->getOpcode() == ISD::UREM ?
+        BuildUDIV(Op.Val, DAG, NULL) :
+        BuildSDIV(Op.Val, DAG, NULL);
+      Tmp1 = DAG.getNode(ISD::MUL, VT, Tmp1, Op.getOperand(1));
+      Tmp1 = DAG.getNode(ISD::SUB, VT, Op.getOperand(0), Tmp1);
+      return Tmp1;
+    }
+    //fall through
+  case ISD::SDIV:
+  case ISD::UDIV:
+    if (MVT::isInteger(Op.getValueType())) {
+      if (Op.getOperand(1).getOpcode() == ISD::Constant)
+        return Op.getOpcode() == ISD::SDIV ? BuildSDIV(Op.Val, DAG, NULL) 
+          : BuildUDIV(Op.Val, DAG, NULL);
+      const char* opstr = 0;
+      switch (Op.getOpcode()) {
+      case ISD::UREM: opstr = "__remqu"; break;
+      case ISD::SREM: opstr = "__remq";  break;
+      case ISD::UDIV: opstr = "__divqu"; break;
+      case ISD::SDIV: opstr = "__divq";  break;
+      }
+      SDOperand Tmp1 = Op.getOperand(0),
+        Tmp2 = Op.getOperand(1),
+        Addr = DAG.getExternalSymbol(opstr, MVT::i64);
+      return DAG.getNode(AlphaISD::DivCall, MVT::i64, Addr, Tmp1, Tmp2);
+    }
+    break;
+
+  case ISD::VAARG: {
+    SDOperand Chain = Op.getOperand(0);
+    SDOperand VAListP = Op.getOperand(1);
+    SrcValueSDNode *VAListS = cast<SrcValueSDNode>(Op.getOperand(2));
+    
+    SDOperand Base = DAG.getLoad(MVT::i64, Chain, VAListP, VAListS->getValue(),
+                                 VAListS->getOffset());
+    SDOperand Tmp = DAG.getNode(ISD::ADD, MVT::i64, VAListP,
+                                DAG.getConstant(8, MVT::i64));
+    SDOperand Offset = DAG.getExtLoad(ISD::SEXTLOAD, MVT::i64, Base.getValue(1),
+                                      Tmp, NULL, 0, MVT::i32);
+    SDOperand DataPtr = DAG.getNode(ISD::ADD, MVT::i64, Base, Offset);
+    if (MVT::isFloatingPoint(Op.getValueType()))
+    {
+      //if fp && Offset < 6*8, then subtract 6*8 from DataPtr
+      SDOperand FPDataPtr = DAG.getNode(ISD::SUB, MVT::i64, DataPtr,
+                                        DAG.getConstant(8*6, MVT::i64));
+      SDOperand CC = DAG.getSetCC(MVT::i64, Offset,
+                                  DAG.getConstant(8*6, MVT::i64), ISD::SETLT);
+      DataPtr = DAG.getNode(ISD::SELECT, MVT::i64, CC, FPDataPtr, DataPtr);
+    }
+
+    SDOperand NewOffset = DAG.getNode(ISD::ADD, MVT::i64, Offset,
+                                      DAG.getConstant(8, MVT::i64));
+    SDOperand Update = DAG.getTruncStore(Offset.getValue(1), NewOffset,
+                                         Tmp, NULL, 0, MVT::i32);
+    
+    SDOperand Result;
+    if (Op.getValueType() == MVT::i32)
+      Result = DAG.getExtLoad(ISD::SEXTLOAD, MVT::i64, Update, DataPtr,
+                              NULL, 0, MVT::i32);
+    else
+      Result = DAG.getLoad(Op.getValueType(), Update, DataPtr, NULL, 0);
+    return Result;
+  }
+  case ISD::VACOPY: {
+    SDOperand Chain = Op.getOperand(0);
+    SDOperand DestP = Op.getOperand(1);
+    SDOperand SrcP = Op.getOperand(2);
+    SrcValueSDNode *DestS = cast<SrcValueSDNode>(Op.getOperand(3));
+    SrcValueSDNode *SrcS = cast<SrcValueSDNode>(Op.getOperand(4));
+    
+    SDOperand Val = DAG.getLoad(getPointerTy(), Chain, SrcP,
+                                SrcS->getValue(), SrcS->getOffset());
+    SDOperand Result = DAG.getStore(Val.getValue(1), Val, DestP, DestS->getValue(),
+                                    DestS->getOffset());
+    SDOperand NP = DAG.getNode(ISD::ADD, MVT::i64, SrcP, 
+                               DAG.getConstant(8, MVT::i64));
+    Val = DAG.getExtLoad(ISD::SEXTLOAD, MVT::i64, Result, NP, NULL,0, MVT::i32);
+    SDOperand NPD = DAG.getNode(ISD::ADD, MVT::i64, DestP,
+                                DAG.getConstant(8, MVT::i64));
+    return DAG.getTruncStore(Val.getValue(1), Val, NPD, NULL, 0, MVT::i32);
+  }
+  case ISD::VASTART: {
+    SDOperand Chain = Op.getOperand(0);
+    SDOperand VAListP = Op.getOperand(1);
+    SrcValueSDNode *VAListS = cast<SrcValueSDNode>(Op.getOperand(2));
+    
+    // vastart stores the address of the VarArgsBase and VarArgsOffset
+    SDOperand FR  = DAG.getFrameIndex(VarArgsBase, MVT::i64);
+    SDOperand S1  = DAG.getStore(Chain, FR, VAListP, VAListS->getValue(),
+                                 VAListS->getOffset());
+    SDOperand SA2 = DAG.getNode(ISD::ADD, MVT::i64, VAListP,
+                                DAG.getConstant(8, MVT::i64));
+    return DAG.getTruncStore(S1, DAG.getConstant(VarArgsOffset, MVT::i64),
+                             SA2, NULL, 0, MVT::i32);
+  }
+  case ISD::RETURNADDR:        
+    return DAG.getNode(AlphaISD::GlobalRetAddr, MVT::i64);
+      //FIXME: implement
+  case ISD::FRAMEADDR:          break;
+  }
+  
+  return SDOperand();
+}
+
+SDOperand AlphaTargetLowering::CustomPromoteOperation(SDOperand Op, 
+                                                      SelectionDAG &DAG) {
+  assert(Op.getValueType() == MVT::i32 && 
+         Op.getOpcode() == ISD::VAARG &&
+         "Unknown node to custom promote!");
+  
+  // The code in LowerOperation already handles i32 vaarg
+  return LowerOperation(Op, DAG);
+}
+
+
+//Inline Asm
+
+/// getConstraintType - Given a constraint letter, return the type of
+/// constraint it is for this target.
+AlphaTargetLowering::ConstraintType 
+AlphaTargetLowering::getConstraintType(const std::string &Constraint) const {
+  if (Constraint.size() == 1) {
+    switch (Constraint[0]) {
+    default: break;
+    case 'f':
+    case 'r':
+      return C_RegisterClass;
+    }
+  }
+  return TargetLowering::getConstraintType(Constraint);
+}
+
+std::vector<unsigned> AlphaTargetLowering::
+getRegClassForInlineAsmConstraint(const std::string &Constraint,
+                                  MVT::ValueType VT) const {
+  if (Constraint.size() == 1) {
+    switch (Constraint[0]) {
+    default: break;  // Unknown constriant letter
+    case 'f': 
+      return make_vector<unsigned>(Alpha::F0 , Alpha::F1 , Alpha::F2 ,
+                                   Alpha::F3 , Alpha::F4 , Alpha::F5 ,
+                                   Alpha::F6 , Alpha::F7 , Alpha::F8 , 
+                                   Alpha::F9 , Alpha::F10, Alpha::F11, 
+                                   Alpha::F12, Alpha::F13, Alpha::F14, 
+                                   Alpha::F15, Alpha::F16, Alpha::F17, 
+                                   Alpha::F18, Alpha::F19, Alpha::F20, 
+                                   Alpha::F21, Alpha::F22, Alpha::F23, 
+                                   Alpha::F24, Alpha::F25, Alpha::F26, 
+                                   Alpha::F27, Alpha::F28, Alpha::F29, 
+                                   Alpha::F30, Alpha::F31, 0);
+    case 'r': 
+      return make_vector<unsigned>(Alpha::R0 , Alpha::R1 , Alpha::R2 , 
+                                   Alpha::R3 , Alpha::R4 , Alpha::R5 , 
+                                   Alpha::R6 , Alpha::R7 , Alpha::R8 , 
+                                   Alpha::R9 , Alpha::R10, Alpha::R11, 
+                                   Alpha::R12, Alpha::R13, Alpha::R14, 
+                                   Alpha::R15, Alpha::R16, Alpha::R17, 
+                                   Alpha::R18, Alpha::R19, Alpha::R20, 
+                                   Alpha::R21, Alpha::R22, Alpha::R23, 
+                                   Alpha::R24, Alpha::R25, Alpha::R26, 
+                                   Alpha::R27, Alpha::R28, Alpha::R29, 
+                                   Alpha::R30, Alpha::R31, 0);
+    }
+  }
+  
+  return std::vector<unsigned>();
+}